Pneumatic tool.



No. 734,276. PATENTED JULY 21, 1903. P. M. METGALF & M. G. ABBEY.

. PNEUMATIC TOOL.

APPLIUATION FILED FEB. 10, 1903.

R0 MODEL. 2 SHEETS-SHEET 1.

FIGS. 'FIBE.

WITNESS-E5- INVENTURS- Mar/9mm WQ/lf/fl WM QM No. 734,276. PATBNTBD JULY 21, 1903';

- F. M. METGALP & M. '0. ABBEY.

PNEUMATIC TOOL.

APPLIOATION PIL'ED FEB. 10, 1903.

NO'MODEL. 2 SHEETS-SHEET 2 UNITED STATES Iatented July 21, 1903.

PATENT O FICE- FOSTER M. METCALF AND MAR-TIN O. ABBEY, OF BATTLEGREEK, MICHIGAN.

PM EU MATIIC oo L.

SPECIFICATION forming part of Letters Patent No. 734,276, dated July 21, 1903.

Application filed February 10, 1903. Serial No. 142,868. (Nb model- To all whmn it may concern: I

Be it known that we, FosrER M. METOALF and MARTIN O. ABBEY, citizens of the United States, residing at Battlecreek, in the county of Calhoun and State of 'Michigan, have invented certain new and useful Improvements in Pneumatic Tools, of which the following is a specification, reference being had therein to the accompanying drawings.

The object of this invention is to provide a pneumatic tool to produce a rapidly-oscillating circular movement, and is more especially intended for grinding check, globe, pump, and other valves to their seats quickly and accurately, but it is obviously applicable to other purposes. In grinding this class of .valves to fit their seatsit has heretofore been the accepted practice to employ hand-labor, partially rotating the valve back and forth by means of a hand-tool While an abrasive mixture is interposed between the surfaces of contact on valve and seat any attempt to accomplish the object by a direct rotary movement in but one direction, either by hand or power, resulting in deep ring grooves and ribs in both valve and seat. By means of our improved device the valve is rotated very rapidly in both directions alternately, resulting in ground surfaces which are perfectly true and free from ring markings and in a time limit far less than required by any other process.

The invention consists in certain novel and advantageous construction and combination of parts relating to the ports or passages and valves used to operate the piston and the rack and pinion whereby motion is communicated to the chuck-spindle, as .will hereinafter more fully be described.

In the accompanying drawings, in which similar parts are designated by like letters of reference, Figure 1 is a sectional elevation showing the main valve'and piston. Fig. 2 is a central vertical section of the same with auxiliary valve and chuck-spindle. Fig. 3 is a plan of the chest-seat on the cylinder with ports and auxiliary valve indicated thereon. Fig. 4 is a horizontal section through the valve-chest. Fig. 5 is the auxiliary valve, and Fig. 6 is a plan of the same. Fig. 7 is a sectional view through chest and cylinder of a modification of the operating parts. Fig.

8 is a horizontal section through chest of the same. Fig. 9 is another modification. These variations will be more fully explained later.

A is the piston, consisting of two separate heads joined by a central hub having a rackgear a formed in one side of it.

, B is the main valve.

C is the auxiliaryvalve'.

D is the valve-chest.

E is the main casing inclosing the two end chambers forming the pneumatic cylinders e e. i F is the chuck-spindle, having bearings in the bracket f, provided with a pinion G at its upper end and retaining-collar 0 below the bracket bearing. The upper end of the chuck-spindle is bored to receive the auxiliary-valve stem and slotted to en gage the driving-pin p. It is thus obvious that the auxiliary valve is positively rotated by the motion of the chuck-spindle. The main valve is provided with four heads or flanges forming three depressions or recesses, the center being the exhaust-cavity communicating with exhaust-passage y. The outside depressions communicate always with direct pressure through air-inlet I and ports 2' 'L' i.

t t are the cylinder-ports.

g g are the trip-ports leading from points near each end of the valve-chest to positions indicated in the valve-seat V.

h h are small holes through the outer valveheads. v

s is the exhaustcavity in the auxiliary valve, and k is the exhaust-port in the auxiliary-valve seat.

W- is a recess or chamber in the valve-chest, arranged to receive the auxiliary valve, and X is a smallhole connecting this chamber with pressure-port i to hold the auxiliary valve to its seat.

The operation is as follows: Pressure being applied to air-inlet I, Fig. 4, it is obvious that the outer depressions in the main valve are both under direct pressure by connection with ports 2' 'i 2'. Now referring to Fig. 1 with the parts in position there shown it is also apparent that both ends of the valvechest are under equal pressure and that cylinder-port t is delivering to the left-hand piston-head, tending to move the piston toward the right. As the piston approaches the right the pinion G is rotated in a contrary direction by means of the rack a and carries with it the auxiliary valve 0 by engagement with its stem 01 and pin 1). Before reaching the end of the stroke this rotary movement brings the cavity 3 underneath the auxiliary valve in position to connect trip-port g and exhaustport it. The main valve is then under the influence of direct pressure upon its right head, while the left is exhausting through the auxiliary valve, ports, and cavity. This will of course cause the main valve to move toward the left and reverse the direction of the piston and its connecting parts.

In the modification shown in Figs. 7 and S the operation is exactly the same, except that the pressure and exhaust cavities in the valve and chest are reversed, and the end chambers are relieved, to reverse the valve, by direct passages to the cylinder, which arenormally closed by extended hoods from the pistonheads and alternately admitted to exhaust near each end of the stroke.

In the modification shown in Fig. 9 the chest and valve in Fig. 8 are used, only omitting the small holes h h in the valve connecting end chest-chambers to pressure. The valve is reversed by direct cylinder-pressure while the opposite end is in exhaust.

The pendent end of the chuck-spindle is arranged to receive suitable chucks to grasp or engage the various pieces it is desired to handle, and the air-inlet is provided with a valve to adjust and regulate the speed as well as to stop and start the machine in operation.

Having thus fully illustrated and described our invention, what we claim as new, and desire to secure by Letters Patent of the United States, is

1. Ina pneumatic tool, the combination of two oppositely-arranged pressure-chainbers, a double-headed piston having one of its heads oscillatingly mounted in each pressure-chamber, supply-chamber in communication with each end of said pressure-chambers, an oscillating controlling-valve mounted in said supply-chamber adapted to control the admission of pressure to the ends of the pressure-chambers, a disk valve rotatably mounted to control the admission of pressure to the supplychamber, a chuck-spindle rotatably mounted and connected with the disk valve and means carried by the main piston for operating the chuck and simultaneously the disk valve.

2. In a pneumatic tool, the combination of a suitable casing having a valve-chest, two oppositely-arranged pressure chambers or cylinders, and a main controlling-valve chamber, arotary valve mounted in said main c011- trolling-valve chamber to control the admission of pressure fluid, an oscillating controlling auxiliary valve mounted in the valvechest to control the admission of pressure to the pressure-cylinders, an oscillating piston having a head mounted in each of said pressure-cylinders, a chuck connected to said main .valve and movable therewith, and means connected to the chuck and in engagement with the oscillating piston for operating the chuck, and the main valve to control the admission of pressure fluid to the valve-chest and consequently the pressure-cylinders.

In a pneumatic tool, a piston having two heads, a central hub joining the same, a rackgear formed upon the hub, a pinion arranged to mesh with the piston-rack, a chuck-spindle attached to the pinion, an auxiliary valve having a stem engagement with the chuckspindle, and a main valve operated from the auxiliary valve, substantially as shown and described.

4. In a pneumatic tool, the piston A working in cylinder-bearings c, c, the rack-gear a, the chuck-spindle F, the pinion G, the auxiliary valve 0, and the main valve B, the valve-chest D, and easing E, together with suitable ports and passages within the same, substantially as shown and described.

In testimony whereof we aflix our signatures in presence of two witnesses.

FOSTER M. METOALF. MARTIN O. ABBEY.

Witnesses:

ALBERT C. PERKINS, J. M. STANNARD. 

